This seems like a perfect example of a trend I've noticed in Apple - they're losing sight of the Paradox of Choice. Who really thinks it's a good idea that a simple accessory like a pencil needs a compatibility matrix?
Apple's always been good about not overwhelming their customers with too many choices - do you want the regular or the Pro model? Laptop, iMac, or Pro Workstation? The product matrix was always really simple to navigate. Almost all other companies require in-depth knowledge of the differences between the X6TRQ, X7RQT, and the 7 similar but slightly different variations, or whatever. Apple was so much better that way.
Now they have way too many choices in each product category, and it keeps getting worse. Accessories like this should have a single version - it's a frickin' pencil. The only question a customer should need to think about is if their device is new enough to be fully compatible.